mushashi is made by tadao, it is just the name of their most recent programming that includes psp style ramping. if you buy new you can either get a tadao 1.1 or a tadao 5.0 w/ mushashi 3, deffinitly get the tadao 5.
Very nice. I'm a big matrix guy, so 9/10. I have the Tadao with the M3 chip and I love it! They have debounce and anti mech bounce, which is really nice.